Security inspection image acquisition method, device, equipment, and storage medium

Abstract

The present application discloses a method, device, equipment, and storage medium for acquiring security inspection images. The method includes: when it is detected that the receiving array element receives a two-dimensional electric scanning target echo signal corresponding to the target step frequency signal emitted by the transmitting array element, an inverse Fourier transform is performed on it to obtain a time domain pulse pressure signal; adaptively search the peak index position values ​​of the transmitting array element and the receiving array element, and calculate their position mean; calculate the distance center coordinate value based on the light speed value, frequency bandwidth, and position mean, and obtain the distance space grid coordinate based on it; divide the distance grid coordinate, and combine it with the preset horizontal and pitch grid coordinates; traverse all grid coordinates to obtain a three-dimensional complex image value; obtain the three-dimensional image modulus value by taking the modulus of the three-dimensional complex image value, and perform image enhancement and three-dimensional maximum projection on it in turn to obtain the target security inspection image. The present application combines pulse compression, distance adaptive space grid division, and image enhancement to obtain the target security inspection image, thereby improving the security inspection efficiency.

Description

Technical Field

[0001] The present application relates to, but is not limited to, the field of millimeter wave imaging technology, and in particular to a security inspection image acquisition method, device, equipment, and storage medium. Background Art

[0002] In public places with large flow of people and high security level, it is necessary to quickly realize the security screening of people entering. Traditional human body security inspection methods mainly rely on metal detectors to identify whether the person to be inspected is carrying contraband, and the staff needs to hold the metal detector to touch the person to be inspected. It is a cooperative security inspection with slow passing speed and cannot be applied to rapid human body security inspection, resulting in low security inspection efficiency. Summary of the invention

[0003] The embodiments of the present application provide a method, apparatus, device, and storage medium for acquiring security inspection images, which can realize rapid acquisition of security inspection images, thereby improving security inspection efficiency.

[0004] In a first aspect, an embodiment of the present application provides a security inspection image acquisition method, which is applied to a control device of a channel-type millimeter wave human body security inspection device, wherein the channel-type millimeter wave human body security inspection device further includes a first transceiver array and a second transceiver array, wherein the first transceiver array and the second transceiver array are aligned in parallel to form a security inspection channel, and the first transceiver array and the second transceiver array each include a plurality of transmitting array elements and a plurality of receiving array elements, and the control device is connected to all of the transmitting array elements and all of the receiving array elements, and the method includes:

[0005] Determining a target stepped frequency signal to be transmitted, and transmitting the target stepped frequency signal through the transmitting array element when a target object is detected to enter the security inspection channel;

[0006] When it is detected that the receiving array element receives a two-dimensional electric scanning target echo signal corresponding to the target stepped frequency signal, an inverse Fourier transform is performed on the target frequency dimension signal to obtain a time domain pulse pressure signal, wherein the two-dimensional electric scanning target echo signal carries the target frequency dimension signal;

[0007] Based on the time domain pulse pressure signal, adaptively search for peak index position values ​​corresponding to all the transmitting array elements and the receiving array elements, and calculate the position mean of all the peak index position values;

[0008] Calculating the distance center coordinate value based on the light speed value, the frequency bandwidth and the position mean value, and obtaining the distance space grid coordinate based on the distance center coordinate value;

[0009] Based on a preset horizontal center zero point and a preset pitch center zero point, dividing the distance space grid coordinates to obtain horizontal grid coordinates and pitch grid coordinates;

[0010] Based on a preset time-domain back-projection algorithm, all of the range-direction space grid coordinates, the horizontal-direction grid coordinates, and the elevation-direction grid coordinates are traversed to obtain three-dimensional space grid complex values, and each of the three-dimensional space grid complex values ​​is modulo-calculated to obtain each three-dimensional image modulus value;

[0011] Based on a preset image enhancement algorithm, resetting the maximum value and the minimum value of the three-dimensional image modulus values ​​that meet the threshold condition to obtain a reference image modulus value;

[0012] Perform three-dimensional maximum projection on the reference image modulus to obtain a target security inspection image.

[0013] In some embodiments, the distance center coordinate value is calculated based on the light speed value, the frequency bandwidth and the position mean, and the distance space grid coordinate is obtained based on the distance center coordinate value, which is obtained according to the following formula:

[0014] [~,Index]=max(d(i,j,t));

[0015] Z mid =mean(Index(i,j))·c / (2B);

[0016] Z=[Z mid -Sampz·Numz2,Z mid +Sampz·Numz2];

[0017] Wherein, d(i,j,t) is the pulse pressure signal of any transceiver channel in the first transceiver array or the second transceiver array, i is the transmit channel index of the first transceiver array or the second transceiver array, j is the receive channel index of the first transceiver array or the second transceiver array, Index is the maximum index value of any transceiver channel, c is the speed of light value, B is the frequency bandwidth, and Z mid is the distance center coordinate value, Sampz is the distance space sampling grid size, Numz is the distance sampling data amount, and Z is the value range corresponding to the distance space grid coordinate.

[0018] In some embodiments, the horizontal grid coordinates and the pitch grid coordinates are divided based on the preset horizontal center zero point and the pitch center zero point, and are obtained according to the following formula:

[0019] X=[-Sampx·Numx2,Sampx·Numx2];

[0020] Y=[-Sampy·Numy2,Sampy·Numy2];

[0021] Among them, Sampx is the horizontal spatial sampling grid size, Numx is the horizontal sampling data amount, Sampy is the pitch spatial sampling grid size, Numy is the pitch sampling data amount, X is the value range of the horizontal grid coordinate, Y is the value range of the pitch grid coordinate, -Sampx·Numx2 is the minimum value of the horizontal value range, Sampx·Numx2 is the maximum value of the horizontal value range, -Sampy·Numy2 is the minimum value of the pitch value range, and Sampy·Numy2 is the maximum value of the pitch value range.

[0022] In some embodiments, the traversing all of the range-direction space grid coordinates, the horizontal-direction grid coordinates, and the elevation-direction grid coordinates based on a preset time-domain back-projection algorithm to obtain three-dimensional space grid complex values ​​includes:

[0023] Based on the time domain backprojection algorithm, all the spatial grid coordinates are traversed in the order of range, elevation and horizontal, and the distance delay from the network node corresponding to the spatial grid coordinate to the transmitting array element and the receiving array element is calculated point by point, and the target phase delay is determined from the distance delay;

[0024] Generate a target echo signal of the corresponding network grid point based on the target phase delay;

[0025] A correlation value between the target echo signal and the time-domain pulse pressure signal is calculated, and the correlation value is determined as a complex value of the three-dimensional space grid.

[0026] In some embodiments, the preset image enhancement algorithm is used to reset the maximum and minimum values ​​of the three-dimensional image modulus values ​​that meet the threshold condition to obtain a reference image modulus value, which is obtained according to the following formula:

[0027] SarIm3DSort=sort(abs(SarIm3D));

[0028]

[0029] SarIm3DSortMin=SarIm3DSort·PerLow;

[0030] SarIm3DSortMax=SarIm3DSort·(1-PerHigh);

[0031] Among them, SarIm3D is the three-dimensional complex image value, abs is used to indicate the modulus operation of the three-dimensional complex image value, sort is used to indicate the ascending order operation, SarIm3DSort(m, n, p) is the reference image modulus value after numerical ascending order, m is the range index value, n is the pitch index value, p is the horizontal index value, SarIm3DSortMin is the minimum threshold value after eliminating the minimum value per thousand, SarIm3DSortMax is the maximum threshold value after eliminating the maximum value per thousand, PerLow is the minimum value per thousand to be eliminated, and PerHigh is the maximum value per thousand to be eliminated.

[0032] In some embodiments, a three-dimensional maximum projection is performed on the reference image modulus to obtain a target security inspection image, which is obtained according to the following formula:

[0033] SarIm2D(n,p)=max(SarIm3DSort(:,n,p));

[0034] Among them, SarIm2D(n,p) is the target security inspection image.

[0035] In a second aspect, an embodiment of the present application provides a channel-type millimeter wave human body security inspection device, including:

[0036] A target stepped frequency signal transmitting module is used to determine the target stepped frequency signal to be transmitted, and when a target object is detected to enter the security inspection channel, the target stepped frequency signal is transmitted through the transmitting array element;

[0037] A time domain pulse pressure signal determination module is used to perform an inverse Fourier transform on the target frequency dimension signal to obtain a time domain pulse pressure signal when it is detected that the receiving array element receives a two-dimensional electric scanning target echo signal corresponding to the target stepped frequency signal, wherein the two-dimensional electric scanning target echo signal carries the target frequency dimension signal;

[0038] A position mean value determination module, configured to adaptively search for peak index position values ​​corresponding to all the transmitting array elements and the receiving array elements based on the time domain pulse pressure signal, and calculate the position mean value of all the peak index position values;

[0039] A distance space grid coordinate determination module, used for calculating the distance center coordinate value based on the light speed value, the frequency bandwidth and the position mean value, and obtaining the distance space grid coordinate based on the distance center coordinate value;

[0040] A module for determining horizontal grid coordinates and elevation grid coordinates, for dividing the distance space grid coordinates to obtain horizontal grid coordinates and elevation grid coordinates based on a preset horizontal center zero point and an elevation center zero point;

[0041] a three-dimensional complex image value determination module, configured to traverse all of the range-direction space grid coordinates, the horizontal-direction grid coordinates, and the elevation-direction grid coordinates based on a preset time-domain back-projection algorithm to obtain three-dimensional space grid complex values, and to obtain each three-dimensional image modulus value by performing modulus calculation on each of the three-dimensional space grid complex values;

[0042] A reference complex image value determination module is used to reset the maximum value and the minimum value of the three-dimensional image modulus values ​​that meet the threshold condition to obtain a reference image modulus value based on a preset image enhancement algorithm;

[0043] The target security inspection image acquisition module is used to perform three-dimensional maximum projection on the reference image modulus to obtain the target security inspection image.

[0044] In a third aspect, an embodiment of the present application provides a control device, comprising at least one control processor and a memory for communicating with the at least one control processor; the memory stores instructions executable by the at least one control processor, and the instructions are executed by the at least one control processor so that the at least one control processor can execute the security image acquisition method described in the first aspect.

[0045] In a fourth aspect, an embodiment of the present application further provides an electronic device, comprising the control device of the second aspect.

[0046] In a fifth aspect, an embodiment of the present application further provides a computer-readable storage medium storing computer-executable instructions, wherein the computer-executable instructions are used to execute the security inspection image acquisition method as described in the first aspect.

[0047] The embodiment of the present application provides a method, device, equipment, and storage medium for acquiring security inspection images. The method is applied to a control device of a channel-type millimeter wave human body security inspection device. The channel-type millimeter wave human body security inspection device also includes a first transceiver array and a second transceiver array. The first transceiver array and the second transceiver array are aligned in parallel to form a security inspection channel. The first transceiver array and the second transceiver array both include multiple transmitting array elements and multiple receiving array elements. The control device is connected to all of the transmitting array elements and all of the receiving array elements. The method includes: determining a target step frequency signal to be transmitted, and when a target object is detected to enter the security inspection channel, transmitting the target step frequency signal through the transmitting array element; when it is detected that the receiving array element receives a two-dimensional electric scanning target echo signal corresponding to the target step frequency signal, performing an inverse Fourier transform on the target frequency dimension signal to obtain a time domain pulse pressure signal, wherein the two-dimensional electric scanning target echo signal carries the target frequency dimension signal. ; Based on the time domain pulse pressure signal, adaptively search for the peak index position values ​​corresponding to all the transmitting array elements and the receiving array elements, and calculate the position mean of all the peak index position values; calculate the distance center coordinate value based on the speed of light value, the frequency bandwidth and the position mean, and obtain the distance space grid coordinate based on the distance center coordinate value; divide the horizontal grid coordinate and the elevation grid coordinate based on the preset horizontal center zero point and the elevation center zero point; traverse all the distance space grid coordinates, the horizontal grid coordinates and the elevation grid coordinates based on the preset time domain back projection algorithm to obtain the three-dimensional space grid complex values, and obtain each three-dimensional image module value by taking the module of each three-dimensional space grid complex value; based on the preset image enhancement algorithm, reset the maximum value and the minimum value of the three-dimensional image module value that meets the threshold condition to obtain the reference image module value; perform three-dimensional maximum projection on the reference image module value to obtain the target security inspection image. According to the solution provided in the embodiment of the present application, based on the channel-type millimeter-wave human body security inspection equipment, pulse compression is combined with a distance-adaptive spatial grid division method and an image enhancement processing method that eliminates maximum and minimum values ​​to obtain a target security inspection image. Compared with the cooperative security inspection method, the security inspection efficiency can be effectively improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 is a flowchart of the steps of a security inspection image acquisition method provided by an embodiment of the present application;

[0049] Figure 2 is a schematic diagram of a channel-type millimeter wave human body security inspection device provided by another embodiment of the present application;

[0050] Figure 3 It is a module schematic diagram of a channel-type millimeter wave human body security inspection device provided by another embodiment of the present application;

[0051] Figure 4 It is a structural diagram of a control device provided in another embodiment of the present application. DETAILED DESCRIPTION

[0052] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0053] It is understood that although the functional modules are divided in the device schematic diagram and the logical order is shown in the flowchart, in some cases, the steps shown or described may be performed in a different order than the module division in the device or the order in the flowchart. The terms "first", "second", etc. in the specification, claims or the above drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0054] In public places with large flow of people and high security level, it is necessary to quickly realize the security screening of people entering. Traditional human body security inspection methods mainly rely on metal detectors to identify whether the person to be inspected is carrying contraband, and the staff needs to hold the metal detector to touch the person to be inspected. It is a cooperative security inspection with slow passing speed and cannot be applied to rapid human body security inspection, resulting in low security inspection efficiency.

[0055] To solve the above-mentioned problems, the embodiments of the present application provide a method, device, equipment, and storage medium for acquiring security inspection images. The method is applied to a control device of a channel-type millimeter wave human body security inspection device. The channel-type millimeter wave human body security inspection device also includes a first transceiver array and a second transceiver array. The first transceiver array and the second transceiver array are aligned in parallel to form a security inspection channel. The first transceiver array and the second transceiver array both include a plurality of transmitting array elements and a plurality of receiving array elements. The control device is connected to all of the transmitting array elements and all of the receiving array elements. The method includes: determining a target step frequency signal to be transmitted, and when a target object is detected to enter the security inspection channel, transmitting the target step frequency signal through the transmitting array element; when it is detected that the receiving array element receives a two-dimensional electric scanning target echo signal corresponding to the target step frequency signal, performing an inverse Fourier transform on the target frequency dimension signal to obtain a time domain pulse pressure signal, wherein the two-dimensional electric scanning target echo signal carries the target frequency dimension signal; Based on the time domain pulse pressure signal, the peak index position values ​​corresponding to all the transmitting array elements and the receiving array elements are adaptively searched, and the position mean of all the peak index position values ​​is calculated; the distance center coordinate value is calculated based on the speed of light value, the frequency bandwidth and the position mean, and the distance space grid coordinate is obtained based on the distance center coordinate value; based on the preset horizontal center zero point and the elevation center zero point, the distance space grid coordinate is divided to obtain the horizontal grid coordinate and the elevation grid coordinate; based on the preset time domain back projection algorithm, all the distance space grid coordinates, the horizontal grid coordinates and the elevation grid coordinates are traversed to obtain the three-dimensional space grid complex values, and each of the three-dimensional space grid complex values ​​is modulo-calculated to obtain each three-dimensional image modulus value; based on the preset image enhancement algorithm, the maximum value and the minimum value of the three-dimensional image modulus value that meets the threshold condition are reset to obtain the reference image modulus value; the reference image modulus value is projected with the three-dimensional maximum value to obtain the target security inspection image. According to the solution provided in the embodiment of the present application, based on the channel-type millimeter-wave human body security inspection equipment, pulse compression is combined with a distance-adaptive spatial grid division method and an image enhancement processing method that eliminates maximum and minimum values ​​to obtain a target security inspection image. Compared with the cooperative security inspection method, the security inspection efficiency can be effectively improved.

[0056] The embodiments of the present application are further described below in conjunction with the accompanying drawings.

[0057] refer to Figure 1 , Figure 1: is a flowchart of the steps of a security inspection image acquisition method provided by an embodiment of the present application. The embodiment of the present application provides a security inspection image acquisition method, which is applied to a control device of a channel-type millimeter wave human body security inspection device. The channel-type millimeter wave human body security inspection device also includes a first transceiver array and a second transceiver array. The first transceiver array and the second transceiver array are aligned in parallel to form a security inspection channel. The first transceiver array and the second transceiver array each include a plurality of transmitting array elements and a plurality of receiving array elements. The control device is connected to all the transmitting array elements and all the receiving array elements. The method includes but is not limited to the following steps:

[0058] Step S110, determining a target stepped frequency signal to be transmitted, and transmitting the target stepped frequency signal through a transmitting array element when a target object is detected to enter a security inspection channel;

[0059] Step S120, when it is detected that the receiving array element receives the two-dimensional electronically scanned target echo signal corresponding to the target stepped frequency signal, an inverse Fourier transform is performed on the target frequency dimension signal to obtain a time domain pulse pressure signal, wherein the two-dimensional electronically scanned target echo signal carries the target frequency dimension signal;

[0060] Step S130, based on the time domain pulse compression signal, adaptively search for peak index position values ​​corresponding to all transmitting array elements and receiving array elements, and calculate the position mean of all peak index position values;

[0061] Step S140, calculating the distance center coordinate value based on the light speed value, the frequency bandwidth and the position mean, and obtaining the distance space grid coordinate based on the distance center coordinate value;

[0062] Step S150, based on the preset horizontal center zero point and the pitch center zero point, dividing the range space grid coordinates to obtain horizontal grid coordinates and pitch grid coordinates;

[0063] Step S160, traversing all the distance space grid coordinates, the horizontal grid coordinates and the elevation grid coordinates based on a preset time domain back-projection algorithm to obtain three-dimensional space grid complex values, and performing module calculation on each three-dimensional space grid complex value to obtain each three-dimensional image module value;

[0064] Step S170, based on a preset image enhancement algorithm, resetting the maximum value and the minimum value of the three-dimensional image modulus values ​​that meet the threshold condition to obtain a reference image modulus value;

[0065] Step S180, performing three-dimensional maximum projection on the reference image modulus value to obtain a target security inspection image.

[0066] It is understandable that the channel-type millimeter wave human body security inspection equipment of the embodiment of the present application can be as follows: Figure 2As shown, the first transceiver array 110 and the second transceiver array 120 are placed parallel to each other to form a security inspection channel. The embodiment of the present application does not limit the distance between the first transceiver array 110 and the second transceiver array 120, which can be 3 meters. Those skilled in the art can adjust it according to actual conditions.

[0067] It should be noted that the expression of the two-dimensional electronic scanning target echo signal, that is, the scattered signal obtained by the millimeter wave two-dimensional electronic scanning in the spatial scanning process is s(xt,xr,yt,yr,f), where xt is the horizontal transmission channel coordinate, x r is the horizontal receiving channel coordinate, yt is the elevation transmitting channel coordinate, y r is the pitch receiving channel coordinate, f is the frequency of the transmitted signal, where f∈[f min ,f max ], f min is the starting frequency of the millimeter wave system transmission, f max It is the millimeter wave system that transmits the termination frequency and obtains the two-dimensional electronic scanning target echo signal. The signal transmission and reception time is very short, and combined with subsequent data processing, it can meet the requirements of real-time security inspection imaging.

[0068] It should be noted that the distance center coordinate value is calculated based on the light speed value, frequency bandwidth and position mean, and the distance space grid coordinate is obtained based on the distance center coordinate value, which is obtained according to the following formula:

[0069] [~,Index]=max(d(i,j,t));

[0070] Z mid =mean(Index(i,j))·c / (2B);

[0071] Z=[Z mid -Sampz·Numz2,Z mid +Sampz·Numz2];

[0072] Wherein, d(i,j,t) is the pulse pressure signal of any transceiver channel in the first transceiver array 110 or the second transceiver array 120, i is the transmit channel index of the first transceiver array 110 or the second transceiver array 120, j is the receive channel index of the first transceiver array 110 or the second transceiver array 120, Index is the maximum index value of any transceiver channel, c is the speed of light, B is the frequency bandwidth, and Z mid is the center coordinate value in the distance direction, Sampz is the distance spatial sampling grid size, Numz is the distance sampling data amount, and Z is the value range corresponding to the distance spatial grid coordinate.

[0073] It should be noted that based on the preset horizontal center zero point and the pitch center zero point, the horizontal grid coordinates and the pitch grid coordinates are divided and obtained according to the following formula:

[0074] X=[-Sampx·Numx2,Sampx·Numx2];

[0075] Y=[-Sampy·Numy2,Sampy·Numy2];

[0076] Among them, Sampx is the horizontal spatial sampling grid size, Numx is the horizontal sampling data amount, Sampy is the pitch spatial sampling grid size, Numy is the pitch sampling data amount, X is the value range of the horizontal grid coordinate, Y is the value range of the pitch grid coordinate, -Sampx·Numx2 is the minimum value of the horizontal value range, Sampx·Numx2 is the maximum value of the horizontal value range, -Sampy·Numy2 is the minimum value of the pitch value range, and Sampy·Numy2 is the maximum value of the pitch value range.

[0077] Additionally, in some embodiments, Figure 1 In step S160, all the distance space grid coordinates, horizontal grid coordinates and elevation grid coordinates are traversed based on the preset time domain back-projection algorithm to obtain the three-dimensional space grid complex value, including but not limited to the following steps:

[0078] Step S161, based on the time domain back-projection algorithm, all the spatial grid coordinates are traversed in the order of range, elevation and horizontal, and the distance delay from the network node corresponding to the spatial grid coordinate to the transmitting array element and the receiving array element is calculated point by point, and the target phase delay is determined from the distance delay;

[0079] Step S162, generating a target echo signal of a corresponding network grid point based on the target phase delay;

[0080] Step S163, calculating the correlation value between the target echo signal and the time domain pulse pressure signal, and determining the correlation value as a three-dimensional space grid complex value.

[0081] It can be understood that the present application traverses all spatial grid coordinates based on the time domain back-projection algorithm, traverses all three-dimensional spatial grid complex values, and the order of the spatial grids is range, pitch, and horizontal, and calculates the distance delay from the network node corresponding to the spatial grid coordinate to the transmitting array element and the receiving array element point by point in this traversal order, determines the target phase delay from the distance delay, and generates the target echo signal of the corresponding network grid point based on the target phase delay, calculates the correlation value between the target echo signal and the time domain pulse pressure signal, and determines the correlation value as the three-dimensional spatial grid complex value SarIm3D(m,n,p), where m in SarIm3D(m,n,p) is the range index value, n is the pitch index value, and p is the horizontal index value, thereby providing an effective data basis for the subsequent acquisition of target security inspection images.

[0082] It should be noted that, based on the preset image enhancement algorithm, the maximum value and the minimum value of the three-dimensional image modulus values ​​that meet the threshold condition are reset to obtain the reference image modulus value, which is obtained according to the following formula:

[0083] SarIm3DSort=sort(abs(SarIm3D));

[0084]

[0085] SarIm3DSortMin=SarIm3DSort·PerLow;

[0086] SarIm3DSortMax=SarIm3DSort·(1-PerHigh);

[0087] Among them, SarIm3D is a three-dimensional complex image value, abs is used to indicate the modulus operation on the three-dimensional complex image value, sort is used to indicate the ascending sorting operation, SarIm3DSort(m, n, p) is the modulus value of the reference image after the numerical value is in ascending order, m is the range index value, n is the pitch index value, p is the horizontal index value, SarIm3DSortMin is the minimum threshold value after eliminating the minimum value per thousand, SarIm3DSortMax is the maximum threshold value after eliminating the maximum value per thousand, PerLow is the minimum value per thousand to be eliminated, and PerHigh is the maximum value per thousand to be eliminated.

[0088] It should be noted that the target security inspection image is obtained by performing a three-dimensional maximum projection on the reference image modulus value, which is obtained according to the following formula:

[0089] SarIm2D(n,p)=max(SarIm3DSort(:,n,p));

[0090] Among them, SarIm2D(n,p) is the target security inspection image.

[0091] In summary, since the security inspection image acquisition method provided in the embodiment of the present application is applied to the control device of the channel type millimeter wave human body security inspection equipment, such as Figure 2 As shown, the channel-type millimeter wave human body security inspection equipment of the embodiment of the present application also includes a first transceiver array 110 and a second transceiver array 120. The first transceiver array 110 and the second transceiver array 120 are aligned in parallel to form a security inspection channel. The first transceiver array 110 and the second transceiver array 120 each include a plurality of transmitting array elements and a plurality of receiving array elements. The control device is connected to all the transmitting array elements and all the receiving array elements. The channel-type millimeter wave human body security inspection equipment has the advantages of large passenger flow, zero contact, no touch, high frame rate, etc., can meet the requirements of real-time imaging, and can effectively improve the security inspection efficiency compared to the cooperative security inspection method. In addition, the steps of acquiring the target security inspection image based on the hardware foundation of the channel-type millimeter-wave human body security inspection equipment in the present application are as follows: determining the target step frequency signal to be transmitted, and when it is detected that the target object 200 enters the security inspection channel, transmitting the target step frequency signal through the transmitting array element; when it is detected that the receiving array element receives the two-dimensional electric scanning target echo signal corresponding to the target step frequency signal, the target frequency dimension signal is inversely Fourier transformed to obtain a time domain pulse pressure signal, wherein the two-dimensional electric scanning target echo signal carries the target frequency dimension signal; based on the time domain pulse pressure signal, adaptively search for the peak index position values ​​corresponding to all the transmitting array elements and the receiving array elements, and calculate the position mean of all the peak index position values; based on the speed of light value, frequency band The distance center coordinate value is calculated based on the width and position mean, and the distance space grid coordinate is obtained based on the distance center coordinate value; the horizontal grid coordinate and the elevation grid coordinate are divided based on the preset horizontal center zero point and the elevation center zero point; based on the preset time domain back projection algorithm, all the distance space grid coordinates, horizontal grid coordinates and elevation grid coordinates are traversed to obtain the three-dimensional space grid complex values, and each three-dimensional space grid complex value is modulo-calculated to obtain each three-dimensional image modulus value; based on the preset image enhancement algorithm, the maximum value and the minimum value in the three-dimensional image modulus value that meets the threshold condition are reset to obtain the reference image modulus value; the reference image modulus value is projected with the three-dimensional maximum value to obtain the target security inspection image. That is to say, the channel-type millimeter-wave human body security inspection equipment based on this embodiment adopts a pulse compression processing method, combined with a distance-dependent adaptive spatial grid division method to obtain the distance position of interest, which can greatly reduce the imaging calculation amount, improve the imaging frame rate, and realize real-time imaging. Through image enhancement and elimination of maximum and minimum value design, the image quality is higher. Compared with cooperative security inspection, the manual security inspection solution can effectively improve the security inspection efficiency and realize rapid security inspection under large traffic conditions.

[0092] In addition, refer to Figure 4 , Figure 4: is a module diagram of a channel-type millimeter wave human body security inspection device provided by another embodiment of the present application. The embodiment of the present application also provides a channel-type millimeter wave human body security inspection device 300, including:

[0093] The target stepped frequency signal transmitting module 310 is used to determine the target stepped frequency signal to be transmitted, and transmit the target stepped frequency signal through the transmitting array element when the target object is detected to enter the security inspection channel;

[0094] The time domain pulse pressure signal determination module 320 is used to perform inverse Fourier transform on the target frequency dimension signal to obtain the time domain pulse pressure signal when it is detected that the receiving array element receives the two-dimensional electric scanning target echo signal corresponding to the target stepped frequency signal, wherein the two-dimensional electric scanning target echo signal carries the target frequency dimension signal;

[0095] The position mean value determination module 330 is used to adaptively search for the peak index position values ​​corresponding to all the transmitting array elements and the receiving array elements based on the time domain pulse pressure signal, and calculate the position mean value of all the peak index position values;

[0096] A distance-direction space grid coordinate determination module 340 is used to calculate the distance-direction center coordinate value based on the light speed value, the frequency bandwidth and the position mean value, and obtain the distance-direction space grid coordinate based on the distance-direction center coordinate value;

[0097] A horizontal grid coordinate and an elevation grid coordinate determining module 350 is used to divide the range space grid coordinates into horizontal grid coordinates and elevation grid coordinates based on a preset horizontal center zero point and an elevation center zero point;

[0098] The three-dimensional complex image value determination module 360 ​​is used to traverse all the range space grid coordinates, the horizontal grid coordinates and the elevation grid coordinates based on a preset time domain back-projection algorithm to obtain the three-dimensional space grid complex values, and to obtain each three-dimensional image modulus value by performing modulus calculation on each three-dimensional space grid complex value;

[0099] A reference image modulus determination module 370 is used to reset the maximum value and the minimum value of the three-dimensional image modulus values ​​that meet the threshold condition to obtain a reference image modulus value based on a preset image enhancement algorithm;

[0100] The target security inspection image acquisition module 380 is used to perform three-dimensional maximum projection on the reference image modulus to obtain the target security inspection image.

[0101] It should be noted that the specific implementation of the channel-type millimeter wave human body security inspection device 300 is basically the same as the specific embodiment of the above-mentioned security inspection image acquisition method, and will not be repeated here.

[0102] like Figure 4 As shown, Figure 4400 is a structural diagram of a control device provided by an embodiment of the present application. The present invention also provides a control device 400, including:

[0103] The processor 410 may be implemented by a general-purpose central processing unit (CPU), a microprocessor, an application-specific integrated circuit (ASIC), or one or more integrated circuits, and is used to execute relevant programs to implement the technical solutions provided in the embodiments of the present application;

[0104] The memory 420 can be implemented in the form of a read-only memory (ROM), a static storage device, a dynamic storage device, or a random access memory (RAM). The memory 420 can store an operating system and other application programs. When the technical solution provided in the embodiment of this specification is implemented by software or firmware, the relevant program code is stored in the memory 420, and the processor 410 calls and executes the security inspection image acquisition method of the embodiment of this application;

[0105] Input / output interface 430, used to implement information input and output;

[0106] Communication interface 440, used to realize communication interaction between the present apparatus and other devices, which can be realized by wired means (such as USB, network cable, etc.) or wireless means (such as mobile network, WIFI, Bluetooth, etc.);

[0107] bus 440 , which transmits information between the various components of the device (e.g., processor 410 , memory 420 , input / output interface 430 , and communication interface 440 );

[0108] The processor 410 , the memory 420 , the input / output interface 430 and the communication interface 440 are connected to each other in communication within the device via the bus 440 .

[0109] In addition, an embodiment of the present application further provides an electronic device, including the control device 400 of the above embodiment.

[0110] In addition, an embodiment of the present application further provides a storage medium, which is a computer-readable storage medium and stores a computer program. When the computer program is executed by a processor, the above-mentioned security inspection image acquisition method is implemented.

[0111] As a non-transient computer-readable storage medium, the memory can be used to store non-transient software programs and non-transient computer executable programs. In addition, the memory may include a high-speed random access memory, and may also include a non-transient memory, such as at least one disk storage device, a flash memory device, or other non-transient solid-state storage devices. In some embodiments, the memory may optionally include a memory remotely arranged relative to the processor, and these remote memories may be connected to the processor via a network. Examples of the above-mentioned networks include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and a combination thereof. The device embodiments described above are merely schematic, wherein the units described as separate components may or may not be physically separated, and are implemented to be located in one place, or may also be distributed to multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the present embodiment.

[0112] It will be appreciated by those skilled in the art that all or some of the steps and systems in the disclosed method above may be implemented as software, firmware, hardware and appropriate combinations thereof. Some physical components or all physical components may be implemented as software executed by a processor, such as a central processing unit, a digital signal processor or a microprocessor, or may be implemented as hardware, or may be implemented as an integrated circuit, such as an application specific integrated circuit. Such software may be distributed on a computer-readable medium, which may include a computer storage medium (or a non-transitory medium) and a communication medium (or a temporary medium). As known to those skilled in the art, the term computer storage medium includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storing information (such as computer-readable instructions, data structures, program modules or other data). Computer storage media include, but are not limited to, RAM, ROM, EEPROM, flash memory or other memory technologies, CD-ROM, digital versatile disks (DVD) or other optical disk storage, magnetic cassettes, magnetic tapes, disk storage or other magnetic storage devices, or any other medium that may be used to store desired information and may be accessed by a computer. Furthermore, it is well known to those skilled in the art that communication media typically include computer readable instructions, data structures, program modules, or other data in a modulated data signal such as a carrier wave or other transport mechanism, and may include any information delivery media.

[0113] The above is a specific description of the preferred implementation of the present invention, but the present invention is not limited to the above-mentioned implementation mode. Technical personnel familiar with the field can also make various equivalent deformations or substitutions under the shared conditions without violating the spirit of the present invention. These equivalent deformations or substitutions are all included in the scope defined by the claims of the present invention.

Claims

1. A method for acquiring security inspection images, characterized in that: A control device applied to a channel-type millimeter wave human body security inspection device, wherein the channel-type millimeter wave human body security inspection device further comprises a first transceiver array and a second transceiver array, wherein the first transceiver array and the second transceiver array are aligned in parallel to form a security inspection channel, wherein the first transceiver array and the second transceiver array both comprise a plurality of transmitting array elements and a plurality of receiving array elements, wherein the control device is connected to all of the transmitting array elements and all of the receiving array elements, and wherein the method comprises: Determining a target stepped frequency signal to be transmitted, and transmitting the target stepped frequency signal through the transmitting array element when a target object is detected to enter the security inspection channel; When it is detected that the receiving array element receives a two-dimensional electric scanning target echo signal corresponding to the target stepped frequency signal, an inverse Fourier transform is performed on the target frequency dimension signal to obtain a time domain pulse pressure signal, wherein the two-dimensional electric scanning target echo signal carries the target frequency dimension signal; Based on the time domain pulse pressure signal, adaptively search for peak index position values ​​corresponding to all the transmitting array elements and the receiving array elements, and calculate the position mean of all the peak index position values; Calculating the distance center coordinate value based on the light speed value, the frequency bandwidth and the position mean value, and obtaining the distance space grid coordinate based on the distance center coordinate value; Based on a preset horizontal center zero point and a preset pitch center zero point, dividing the distance space grid coordinates to obtain horizontal grid coordinates and pitch grid coordinates; Based on a preset time-domain back-projection algorithm, all of the range-direction space grid coordinates, the horizontal-direction grid coordinates, and the elevation-direction grid coordinates are traversed to obtain three-dimensional space grid complex values, and each of the three-dimensional space grid complex values ​​is modulo-calculated to obtain each three-dimensional image modulus value; Based on a preset image enhancement algorithm, resetting the maximum value and the minimum value of the three-dimensional image modulus values ​​that meet the threshold condition to obtain multiple reference image modulus values; Performing three-dimensional maximum projection on the reference image modulus value to obtain a target security inspection image; Among them, based on the preset image enhancement algorithm, the maximum value and the minimum value of the three-dimensional image model value that meet the threshold condition are reset to obtain the reference image model value, which is obtained according to the following formula: SarIm3DSort=sort(abs(SarIm3D)); SarIm3DSortMin=SarIm3DSort·PerLow; SarIm3DSortMax=SarIm3DSort·(1-PerHigh); Among them, SarIm3D is the complex value of the three-dimensional space grid, abs is used to indicate the modulus operation on the complex value of the three-dimensional space grid, sort is used to indicate the ascending order operation, SarIm3DSort(m, n, p) is the modulus value of the reference image after the values ​​are in ascending order, m is the range index value, n is the pitch index value, p is the horizontal index value, SarIm3DSortMin is the minimum threshold value after eliminating the minimum value per thousand, SarIm3DSortMax is the maximum threshold value after eliminating the maximum value per thousand, PerLow is the minimum value per thousand to be eliminated, and PerHigh is the maximum value per thousand to be eliminated.

2. The security inspection image acquisition method according to claim 1, characterized in that: The distance center coordinate value is calculated based on the light speed value, the frequency bandwidth and the position mean, and the distance space grid coordinate is obtained based on the distance center coordinate value, which is obtained according to the following formula: Z mid =mean(Index(i,j))·c / (2B); Z=[Z mid -Sampz·Numz / 2,Z mid +Sampz·Numz / 2]; Wherein, the maximum signal value in the pulse pressure signal of any transceiver channel in the first transceiver array or the second transceiver array is determined, and the index value corresponding to the maximum signal value is determined as the maximum index value Index of any transceiver channel, i is the transmit channel index of the first transceiver array or the second transceiver array, j is the receive channel index of the first transceiver array or the second transceiver array, c is the light speed value, B is the frequency bandwidth, and Z mid is the distance center coordinate value, Sampz is the distance space sampling grid size, Numz is the distance sampling data amount, and Z is the value range corresponding to the distance space grid coordinate.

3. The security inspection image acquisition method according to claim 1, characterized in that: The horizontal grid coordinates and the pitch grid coordinates are divided based on the preset horizontal center zero point and the pitch center zero point, and are obtained according to the following formula: X=[-Sampx·Numx / 2,Sampx·Numx / 2]; Y=[-Sampy·Numy / 2,Sampy·Numy / 2]; Among them, Sampx is the horizontal spatial sampling grid size, Numx is the horizontal sampling data amount, Sampy is the pitch spatial sampling grid size, Numy is the pitch sampling data amount, X is the value range of the horizontal grid coordinate, Y is the value range of the pitch grid coordinate, -Sampx·Numx / 2 is the minimum value of the horizontal value range, Sampx·Numx / 2 is the maximum value of the horizontal value range, -Sampy·Numy / 2 is the minimum value of the pitch value range, and Sampy·Numy / 2 is the maximum value of the pitch value range.

4. The security inspection image acquisition method according to claim 1, characterized in that: The preset time-domain back-projection algorithm traverses all the range-direction space grid coordinates, the horizontal-direction grid coordinates, and the elevation-direction grid coordinates to obtain three-dimensional space grid complex values, including: Based on the time domain backprojection algorithm, all the spatial grid coordinates are traversed in the order of range, elevation and horizontal, and the distance delay from the grid node corresponding to the spatial grid coordinate to the transmitting array element and the receiving array element is calculated point by point, and the target phase delay is determined from the distance delay; Generate a target echo signal of the corresponding grid node based on the target phase delay; A correlation value between the target echo signal and the time-domain pulse pressure signal is calculated, and the correlation value is determined as a complex value of the three-dimensional space grid.

5. The security inspection image acquisition method according to claim 1, characterized in that: Perform three-dimensional maximum projection on the reference image modulus to obtain the target security inspection image, which is obtained according to the following formula: Sar Im 2D(n,p)=max(Sar Im 3DSort(m,n,p)); Among them, SarIm2D(n,p) is the target security inspection image.

6. A channel-type millimeter wave human body security inspection equipment, characterized in that: include: A target stepped frequency signal transmitting module is used to determine the target stepped frequency signal to be transmitted, and transmit the target stepped frequency signal through the transmitting array element when the target object is detected to enter the security inspection channel; A time domain pulse pressure signal determination module is used to perform an inverse Fourier transform on the target frequency dimension signal to obtain a time domain pulse pressure signal when it is detected that the receiving array element receives a two-dimensional electric scanning target echo signal corresponding to the target stepped frequency signal, wherein the two-dimensional electric scanning target echo signal carries the target frequency dimension signal; A position mean value determination module, configured to adaptively search for peak index position values ​​corresponding to all the transmitting array elements and the receiving array elements based on the time domain pulse pressure signal, and calculate the position mean value of all the peak index position values; A distance space grid coordinate determination module, used for calculating the distance center coordinate value based on the light speed value, the frequency bandwidth and the position mean value, and obtaining the distance space grid coordinate based on the distance center coordinate value; A module for determining horizontal grid coordinates and elevation grid coordinates, for dividing the distance space grid coordinates to obtain horizontal grid coordinates and elevation grid coordinates based on a preset horizontal center zero point and an elevation center zero point; a three-dimensional complex image value determination module, configured to traverse all of the range-direction space grid coordinates, the horizontal-direction grid coordinates, and the elevation-direction grid coordinates based on a preset time-domain back-projection algorithm to obtain three-dimensional space grid complex values, and to obtain each three-dimensional image modulus value by performing modulus calculation on each of the three-dimensional space grid complex values; A reference image modulus determination module, used to reset the maximum and minimum values ​​in the three-dimensional modulus image that meets the threshold condition to obtain a reference image modulus based on a preset image enhancement algorithm; A target security inspection image acquisition module is used to perform a three-dimensional maximum projection on the reference image modulus to obtain a target security inspection image; Among them, based on the preset image enhancement algorithm, the maximum value and the minimum value of the three-dimensional image model value that meet the threshold condition are reset to obtain the reference image model value, which is obtained according to the following formula: SarIm3DSort=sort(abs(SarIm3D)); SarIm3DSortMin=SarIm3DSort·PerLow; SarIm3DSortMax=SarIm3DSort·(1-PerHigh); Among them, SarIm3D is the complex value of the three-dimensional space grid, abs is used to indicate the modulus operation on the complex value of the three-dimensional space grid, sort is used to indicate the ascending order operation, SarIm3DSort(m, n, p) is the modulus value of the reference image after the values ​​are in ascending order, m is the range index value, n is the pitch index value, p is the horizontal index value, SarIm3DSortMin is the minimum threshold value after eliminating the minimum value per thousand, SarIm3DSortMax is the maximum threshold value after eliminating the maximum value per thousand, PerLow is the minimum value per thousand to be eliminated, and PerHigh is the maximum value per thousand to be eliminated.

7. A control device, characterized in that: It includes at least one control processor and a memory for communicating with the at least one control processor; the memory stores instructions that can be executed by the at least one control processor, and the instructions are executed by the at least one control processor so that the at least one control processor can execute the security inspection image acquisition method as described in any one of claims 1 to 5.

8. An electronic device, characterized in that: Comprising the control device as claimed in claim 7.

9. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer-executable instructions, and the computer-executable instructions are used to enable a computer to execute the security inspection image acquisition method according to any one of claims 1 to 5.

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